curl: A Modern and Flexible Web Client for R

The curl() and curl_download() functions provide highly
configurable drop-in replacements for base url() and download.file() with
better performance, support for encryption (https, ftps), gzip compression,
authentication, and other 'libcurl' goodies. The core of the package implements a
framework for performing fully customized requests where data can be processed
either in memory, on disk, or streaming via the callback or connection
interfaces. Some knowledge of 'libcurl' is recommended; for a more-user-friendly
web client see the 'httr' package which builds on this package with http
specific tools and logic.